System is ...Windows 7 .....Sonar Producer 7 .....

All other pieces work FINE with no problems.

But one particular important sequence continually crashes ..it plays fine but on "STOP " the whole thing crashes the PC.

Everything has been stripped ..no audio effects etc/inserts/ ...just the bare bone Midi tracks and audio tracks. No busses, no plug ins or soft synths.

I'm assuming maybe one of the audio tracks is corrupted ? Is there any way to find it and save the piece ?

Foot note.......oh no ! ......it's starting to crash on other sequences. ....

I just got Focusrite Scarlet...I hope it's not that causing the problem....I suspect it might be....

Hi. Do you have the latest ASIO drivers for your Focusrite? Is your windows up to date? Have you tried a different USB port, or cable? 
Best of luck.

Thanks for your reply and help....

Yes...I am suspecting the Focusrite Scarlet and not now the sequence .....

I will try your suggestions and new drivers..,strange but I keep getting a message saying my system only supports Windows audio (the WDM ) at 16 bit...yet I just had this custom PC made up for audio in January and paid £500 ...

I cannot determine if I should be using ASIO with regards to this message

You should use ASIO

This is what I thought...but I get no audio with ASIO....only on WDM...no matter what I do .

It def is not the sequence ..it's the Focusrite Scarlet causing the issue after seemingly functioning Okay..

I've got latest drivers from Focusrite. The system now seems stable BUT only works with WDM NOT ASIO

I'll keep trying whatever options there is until I've tried them all. I could possibly be missing something.

Have you tried restarting your pc after updating drivers? What (steps) did you do when opening SONAR (after installing Focusrite ASIO drivers)?
Did you try different USB port?
It is hopefully just a minor thing.
The more info, the easier to help.

Yes...I have done as you advised there...thanks

The system seems stable and no more instant shutdowns...but I haven't used ASIO....I'm using WDM....I'll try more options tomorrow to get things stable and running with ASIO .

Thanks again for help